Modern stator manufacturing production lines include several different stations at which different manufacturing operations are performed. One such operation that is frequently accomplished at an early stage in the process of manufacturing a 2-pole stator is to assemble terminal members, either stator coil terminals or supports for stator coil terminals, on an unwound stator core. After the terminal members are assembled onto the stator core, a pair of stator coils are wound on the stator core pole pieces at a stator winding station using magnet wire having an electrically insulating coating. A common practice is to temporarily clamp the stator coil lead wires to wire clamps during the winding process. At a later manufacturing stage, the lead wires are connected to the terminal members on the stator core at a coil lead terminating station.
One type of stator manufacturing apparatus, which is disclosed in the above-mentioned Banner et al. U.S. Pat. No. 5,090,108, includes a support track along which unwound stators having cores on which terminal members have previously been assembled are moved to a stator winding station at which the stator coils are wound. The freshly wound stators are then moved along the support track to a coil lead terminating station at which the stator coil lead wires are connected to the terminal members on the core. Lead pull assemblies at the winding station have wire grippers which are manipulated to place the stator coil lead wires into temporary wire clamps. While maintaining their grip on the lead wires, the temporary wire clamps are moved to the coil lead terminating station along with the wound stator. Mechanisms at the coil lead terminating station remove the stator coil lead wires from the temporary wire clamps and connect them to the terminal members on the stator core.
An industrial robot is now commonly used to effect the terminal connections at the coil lead terminating station. Robots used for making the terminal connections are highly reliable and fast acting, but connect the lead wires to the stator terminal members one at a time. Each terminal connection is made by using the end effector of the robot to grip one of the coil lead wires and retract it from its associated temporary wire clamp. The end effector is then manipulated as required to effect a connection to the terminal member on the stator core. Typically, it may take four seconds or so for the end effector to complete the connection of a single lead wire to the terminal member.
There are cases in which the winding procedures that take place at the winding station will be done faster than all of the lead wires can be connected to the terminal members at the coil lead terminating station. In such cases, the winding operations must be interrupted after the winding of coils on a stator at the stator winding station and not resumed until after completion of the lead wire connections to all of the terminal members on the next previously wound stator at the coil lead terminating station and the subsequent transfer of the newly wound stator to the coil lead terminating station. Thus, the cycle time during which a stator is wound at the winding station and the coil lead wires are terminated at the coil lead terminating station includes an interval of time during which both the coil winding mechanisms and the coil lead connect mechanisms are idle while the transfer assembly is operated to disengage the stator at the coil lead terminating station, return to coil winding station, engage the stator at the winding station and, with assistance of a lead pull assembly at the winding station, temporarily grip the lead wires extending from the freshly wound stator. This interval of time is not particularly long, on the order of two to four seconds for each stator, but can be of substantial significance over an extended period during which stators are mass produced.